In a paper appearing this week (Aug. 23) in the journal Nature Communications, Krupenkin and Taylor, both engineering researchers at the University of Wisconsin-Madison, describe a new energy-harvesting technology that promises to dramatically reduce our dependence on batteries and instead capture the energy of human motion to power portable electronics.
They have novel energy-harvesting technology known as “reverse electrowetting,” a phenomenon discovered by the Wisconsin researchers. The mechanical energy is converted to electrical energy by using a micro-fluidic device consisting of thousands of liquid micro-droplets interacting with a novel nano-structured substrate.
This technology could enable a novel footwear-embedded energy harvester that captures energy produced by humans during walking, which is normally lost as heat, and converts it into up to 20 watts of electrical power that can be used to power mobile electronic devices. Unlike a traditional battery, the energy harvester never needs to be recharged, as the new energy is constantly generated during the normal walking process.
The energy generated by the footwear-embedded harvester can be used in one of two ways. It can be used directly to power a broad range of devices, from smartphones and laptops to radios, GPS units, night-vision goggles and flashlights.
Alternatively, the energy harvester can be integrated with a Wi-Fi hot spot that acts as a “middleman” between mobile devices and a wireless network. This allows users to seamlessly utilize the energy generated by the harvester without having to physically connect their mobile devices to the footwear. Such a configuration dramatically reduces power consumption of wireless mobile devices and allows them to operate for much longer time without battery recharge, the Wisconsin researchers say.
“You cut the power requirements of your cellphone dramatically by doing this,” says Krupenkin. “Your cellphone battery will last 10 times longer.”
Even though energy harvesting is unlikely to completely replace batteries in the majority of mobile applications, the UW-Madison researchers believe it can play a key role in reducing cost, pollution and other problems associated with battery use. The hope, they say, is that the novel mechanical to electrical energy conversion process they pioneered can go a long way toward achieving that goal.